LEAD FRAME AND ASSEMBLY STRUCTURE
A lead frame includes a die paddle, a first lead, a second lead, an extending portion and at least one supporting portion. The first lead includes a first main portion and a first I/O portion opposite to the first main portion. The second lead includes a second main portion and a second I/O portion opposite to the second main portion. The first lead and the second lead surround the die paddle. The extending portion extends from the first main portion of the first lead. The supporting portion is connected to the extending portion.
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The present disclosure relates to a lead frame and an assembly structure, and to a lead frame including a plurality of leads surrounding a die paddle, and an assembly structure including the lead frame.
DESCRIPTION OF THE RELATED ARTAs for a semiconductor package such as a quad flat non-leaded package (QFN), a length of each of the leads that surround a die paddle is limited and cannot be further lengthened since the structural strength of the lead becomes weak after manufacturing. Thus, the leads may deform, bend or break during a molding process, and the bonding wires that are bonded on the leads may break or contact with each other to cause a short circuit. However, lengthening the length of the lead may be required when a smaller semiconductor die is attached to the die paddle, to ensure the leads may be still near the smaller semiconductor die and prevent the bonding wire from being longer than its optimum length.
SUMMARYIn some embodiments, a lead frame includes a die paddle, a first lead, a second lead, an extending portion and at least one supporting portion. The first lead includes a first main portion and a first I/O portion opposite to the first main portion. The second lead includes a second main portion and a second I/O portion opposite to the second main portion. The first lead and the second lead surround the die paddle. The extending portion extends from the first main portion of the first lead. The supporting portion is connected to the extending portion.
In some embodiments, a lead frame includes a die paddle, a plurality of leads, an extending portion and at least one supporting portion. The leads surround the die paddle. The leads include a first lead and a third lead. The first lead includes a first main portion and a first I/O portion opposite to the first main portion. The third lead includes a third main portion and a third I/O portion opposite to the third main portion. The extending portion connects the first main portion of the first lead and the third main portion of the third lead. The supporting portion protrudes from the extending portion.
In some embodiments, an assembly structure includes a substrate and a package structure. The substrate has a top surface and a bottom surface opposite to the top surface. The package structure is disposed adjacent to the top surface of the substrate. The package structure includes a die paddle, a semiconductor die, a first lead, a second lead, an extending portion, at least one supporting portion, a plurality of bonding wires and an encapsulant. The semiconductor die is disposed on the die paddle. The first lead includes a first main portion and a first I/O portion opposite to the first main portion. The second lead includes a second main portion and a second I/O portion opposite to the second main portion. The first lead and the second lead surround the die paddle. The extending portion extends from the first main portion of the first lead. The supporting portion is connected to the extending portion. The bonding wires are used for electrically connecting the semiconductor die to the first lead and the second lead. The encapsulant covers the semiconductor die, the die paddle, the first lead, the second lead, the extending portion, the at least one supporting portion and the bonding wires. A bottom surface of the first I/O portion and a bottom surface of the second I/O portion are bonded to the substrate through a soldering material.
Aspects of some embodiments of the present disclosure are readily understood from the following detailed description when read with the accompanying figures. It is noted that various structures may not be drawn to scale, and dimensions of the various structures may be arbitrarily increased or reduced for clarity of discussion.
Common reference numerals are used throughout the drawings and the detailed description to indicate the same or similar components. Embodiments of the present disclosure will be readily understood from the following detailed description taken in conjunction with the accompanying drawings.
The following disclosure provides many different embodiments, or examples, for implementing different features of the provided subject matter. Specific examples of components and arrangements are described below to explain certain aspects of the present disclosure. These are, of course, merely examples and are not intended to be limiting. For example, the formation of a first feature over or on a second feature in the description that follows may include embodiments in which the first and second features are formed or disposed in direct contact, and may also include embodiments in which additional features may be formed or disposed between the first and second features, such that the first and second features may not be in direct contact. In addition, the present disclosure may repeat reference numerals and/or letters in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed.
In some embodiments, the supporting portion 25 is connected to the extending portion 24. For example, the first lead 20a, the extending portion 24 and the supporting portion 25 may be formed integrally as a monolithic structure. The extending portion 24 may extend from the supporting portion 25 downwardly. Thus, a top surface 211a of the first main portion 21a may be substantially coplanar with a top surface 241 of the extending portion 24 and the top surface 11 of the die paddle 10. A bottom surface 222a of the first I/O portion 22a may be substantially coplanar with a bottom surface 252 of the supporting portion 25 and the bottom surface 12 of the die paddle 10. In addition, a thickness t2 of the first I/O portion 22a may be substantially equal to a sum thickness t5 of a thickness t6 of the extending portion 24 and a thickness t7 of the supporting portion 25. The thickness t1 of the first main portion 21a may be substantially equal to the thickness t6 of the extending portion 24.
In some embodiments, as shown in
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In some embodiments, the first lead 20a, the third lead 20c, the extending portion 24 and the supporting portion(s) 25 are formed integrally as a monolithic structure. An electric potential of the first lead 20a may be equal to an electric potential of the third lead 20c. Further, the second lead 20b may be separated from the extending portion 24. Thus, an electric potential of the second lead 20b may be different from the electric potential of the first lead 20a and the third lead 20c. In addition, a length of the first main portion 21a of the first lead 20a or a length of the third main portion 21c of the third lead 20c may be greater than a length of the second main portion 21b of the second lead 20b. As shown in
As shown in
In some embodiments, the supporting portion 25d is connected to the extending portion 24d. For example, the first lead 20d, the extending portion 24d and the supporting portion 25d may be formed integrally as a monolithic structure. The extending portion 24d may extend from the supporting portion 25d downwardly. An extending direction 26e of the bonding portion 23e (e.g., a bonding end) of the second lead 20e may extend across the extending portion 24d. In addition, the first main portion 21d of the first lead 20d is disposed adjacent to and spaced apart from the die paddle 10, and the bonding portion 23e of the second main portion 21e of the second lead 20e is disposed adjacent to and spaced apart from the die paddle 10. The extending portion 24d extends from the first main portion 21d of the first lead 20d, and a portion of the extending portion 24d may be disposed between the die paddle 10 and the bonding portion 23e of the second main portion 21e of the second lead 20e. As shown in
In some embodiments, the supporting portion 25f is connected to the extending portion 24f For example, the first lead 20f, the extending portion 24f and the supporting portion 25f may be formed integrally as a monolithic structure. The extending portion 24f may extend from the supporting portion 25f downwardly. An extending direction 26g of the bonding portion 23g (e.g., a bonding end) of the second lead 20g may extend across the extending portion 24f In addition, the first main portion 21f of the first lead 20f is disposed adjacent to and spaced apart from the die paddle 10, and the bonding portion 23g of the second main portion 21g of the second lead 20g is disposed adjacent to and spaced apart from the die paddle 10. The extending portion 24f extends from the first main portion 21f of the first lead 20f, and a portion of the extending portion 24f may be disposed between the die paddle 10 and the bonding portion 23g of the second main portion 21g of the second lead 20g. As shown in
As shown in
In the embodiment illustrated in
The encapsulant 70 (e.g., a molding compound) covers the semiconductor die 50, the die paddle 10, the leads 20 (e.g., the first lead 20a, the second lead 20b and the third lead 20c), the extending portion(s) 24, 24d, 24f, the at least one supporting portion 25, 25d, 25f and the bonding wires 60. In some embodiments, the bottom surface 72 of the encapsulant 70 may be substantially coplanar with the bottom surface of the I/O portion 22 of the leads 20, the bottom surfaces of the supporting portions 25, 25d, 25f, and the bottom surface 12 of the die paddle 10. For example, the bottom surface 222a of the first I/O portion 22a, the bottom surface 222b of the second I/O portion 22b, the bottom surface of the third I/O portion 22c, the bottom surface 252 of the supporting portion 25 and the bottom surface 12 of the die paddle 10 may be substantially coplanar with the bottom surface 72 of the encapsulant 70, and may be exposed from the bottom surface 72 of the encapsulant 70.
In some embodiments, a bonding layer may be formed or disposed on the exposed bottom surface of the I/O portion 22 of the leads 20, the exposed bottom surfaces of the supporting portions 25, 25d, 25f, and the exposed bottom surface 12 of the die paddle 10. The bonding layer may include at least one metal layer, and a material of the at least one metal layer may be nickel (Ni), palladium (Pd), gold (Au), silver (Ag), and/or pre-solder.
In some embodiments, the supporting portions 25, 25d, 25f are embedded in the encapsulant 70 so as to improve the bonding between the lead frame 9 (or the lead frame unit 1) and the encapsulant 70. That is, the supporting portions 25, 25d, 25f may have the locking function.
The package structure 3 of
Spatial descriptions, such as “above,” “below,” “up,” “left,” “right,” “down,” “top,” “bottom,” “vertical,” “horizontal,” “side,” “higher,” “lower,” “upper,” “over,” “under,” and so forth, are indicated with respect to the orientation shown in the figures unless otherwise specified. It should be understood that the spatial descriptions used herein are for purposes of illustration only, and that practical implementations of the structures described herein can be spatially arranged in any orientation or manner, provided that the merits of embodiments of this disclosure are not deviated from by such an arrangement.
As used herein, the terms “approximately,” “substantially,” “substantial” and “about” are used to describe and account for small variations. When used in conjunction with an event or circumstance, the terms can refer to instances in which the event or circumstance occurs precisely as well as instances in which the event or circumstance occurs to a close approximation. For example, when used in conjunction with a numerical value, the terms can refer to a range of variation of less than or equal to ±10% of that numerical value, such as less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.1%, or less than or equal to ±0.05%. For example, a first numerical value can be deemed to be “substantially” the same or equal to a second numerical value if the first numerical value is within a range of variation of less than or equal to ±10% of the second numerical value, such as less than or equal to ±5%, less than or equal to ±4%, less than or equal to ±3%, less than or equal to ±2%, less than or equal to ±1%, less than or equal to ±0.5%, less than or equal to ±0.1%, or less than or equal to ±0.05%.
Two surfaces can be deemed to be coplanar or substantially coplanar if a displacement between the two surfaces is no greater than 5 μm, no greater than 2 μm, no greater than 1 μm, or no greater than 0.5 μm. A surface can be deemed to be substantially flat if a displacement between a highest point and a lowest point of the surface is no greater than 5 μm, no greater than 2 μm, no greater than 1 μm, or no greater than 0.5 μm.
As used herein, the singular terms “a,” “an,” and “the” may include plural referents unless the context clearly dictates otherwise.
As used herein, the terms “conductive,” “electrically conductive” and “electrical conductivity” refer to an ability to transport an electric current. Electrically conductive materials typically indicate those materials that exhibit little or no opposition to the flow of an electric current. One measure of electrical conductivity is Siemens per meter (S/m). Typically, an electrically conductive material is one having a conductivity greater than approximately 104 S/m, such as at least 105 S/m or at least 106 S/m. The electrical conductivity of a material can sometimes vary with temperature. Unless otherwise specified, the electrical conductivity of a material is measured at room temperature.
Additionally, amounts, ratios, and other numerical values are sometimes presented herein in a range format. It is to be understood that such range format is used for convenience and brevity and should be understood flexibly to include numerical values explicitly specified as limits of a range, but also to include all individual numerical values or sub-ranges encompassed within that range as if each numerical value and sub-range is explicitly specified.
While the present disclosure has been described and illustrated with reference to specific embodiments thereof, these descriptions and illustrations are not limiting. It should be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the true spirit and scope of the present disclosure as defined by the appended claims. The illustrations may not be necessarily drawn to scale. There may be distinctions between the artistic renditions in the present disclosure and the actual apparatus due to manufacturing processes and tolerances. There may be other embodiments of the present disclosure which are not specifically illustrated. The specification and drawings are to be regarded as illustrative rather than restrictive. Modifications may be made to adapt a particular situation, material, composition of matter, method, or process to the objective, spirit and scope of the present disclosure. All such modifications are intended to be within the scope of the claims appended hereto. While the methods disclosed herein have been described with reference to particular operations performed in a particular order, it will be understood that these operations may be combined, sub-divided, or re-ordered to form an equivalent method without departing from the teachings of the present disclosure. Accordingly, unless specifically indicated herein, the order and grouping of the operations are not limitations of the present disclosure.
Claims
1. A lead frame, comprising:
- a die paddle;
- a first lead including a first main portion and a first I/O portion opposite to the first main portion;
- a second lead including a second main portion and a second I/O portion opposite to the second main portion, wherein the first lead and the second lead surround the die paddle;
- an extending portion extending from the first main portion of the first lead; and
- at least one supporting portion connected to the extending portion.
2. The lead frame of claim 1, wherein the second lead has an end side surface opposite to the second I/O portion, and the end side surface of the second lead faces the extending portion.
3. The lead frame of claim 1, wherein the second main portion of the second lead includes a bonding portion opposite to the second I/O portion, and an extending direction of the bonding portion extends across the extending portion.
4. The lead frame of claim 1, wherein the first main portion is disposed adjacent to and spaced apart from the die paddle, the second main portion is disposed adjacent to and spaced apart from the die paddle, and a portion of the extending portion is disposed between the die paddle and the second main portion of the second lead.
5. The lead frame of claim 1, wherein a thickness t2 of the first I/O portion is greater than a thickness of the first main portion, and a thickness of the second I/O portion is greater than a thickness of the second main portion.
6. The lead frame of claim 1, wherein a thickness of the first I/O portion is substantially equal to a sum thickness of a thickness of the extending portion and a thickness of the supporting portion.
7. The lead frame of claim 1, further comprising a third lead including a third main portion and a third I/O portion opposite to the third main portion, the second lead is disposed between the first lead and the third lead, and the extending portion connects to the third main portion of the third lead.
8. The lead frame of claim 1, wherein the extending portion is substantially parallel with a side surface of the die paddle.
9. The lead frame of claim 1, wherein the at least one supporting portion includes a plurality of supporting portions, and a gap between two adjacent supporting portions is greater than or equal 0.2 mm.
10. The lead frame of claim 1, wherein a gap between a side surface of the die paddle and the at least one supporting portion is greater than or equal 0.2 mm.
11. A lead frame, comprising:
- a die paddle;
- a plurality of leads surrounding the die paddle, wherein the leads includes: a first lead including a first main portion and a first I/O portion opposite to the first main portion; and a third lead including a third main portion and a third I/O portion opposite to the third main portion;
- an extending portion connecting the first main portion of the first lead and the third main portion of the third lead; and
- at least one supporting portion protruding from the extending portion.
12. The lead frame of claim 11, wherein an electric potential of the first lead is equal to an electric potential of the third lead.
13. The lead frame of claim 11, wherein the leads further includes a second lead disposed between the first lead and the third lead, and separated from the extending portion.
14. The lead frame of claim 13, wherein the second lead includes a second main portion and a second I/O portion opposite to the second main portion, and a length of the first main portion of the first lead is greater than a length of the second main portion of the second lead.
15. An assembly structure, comprising:
- a substrate having a top surface and a bottom surface opposite to the top surface; and
- a package structure disposed adjacent to the top surface of the substrate, and comprising: a die paddle; a semiconductor die disposed on the die paddle; a first lead including a first main portion and a first I/O portion opposite to the first main portion; a second lead including a second main portion and a second I/O portion opposite to the second main portion, wherein the first lead and the second lead surround the die paddle; an extending portion extending from the first main portion of the first lead; and at least one supporting portion connected to the extending portion;
- a plurality of bonding wires electrically connecting the semiconductor die to the first lead and the second lead; and
- an encapsulant covering the semiconductor die, the die paddle, the first lead, the second lead, the extending portion, the at least one supporting portion and the bonding wires, wherein a bottom surface of the first I/O portion and a bottom surface of the second I/O portion are bonded to the substrate through a soldering material.
16. The assembly structure of claim 15, wherein the bonding wires includes a first wire bonded to the extending portion, and a second wire bonded to the second main portion of the second lead.
17. The assembly structure of claim 15, wherein at least two of the bonding wires are bonded to the extending portion.
18. The assembly structure of claim 15, wherein a bottom surface of the first I/O portion, a bottom surface of the second I/O portion and a bottom surface of the at least one supporting portion are exposed from a bottom surface of the encapsulant.
19. The assembly structure of claim 15, wherein the extending portion connects to a third lead.
20. The assembly structure of claim 15, wherein a space between a bottom surface of the at least one supporting portion and the top surface of the substrate is empty.
Type: Application
Filed: Jan 22, 2020
Publication Date: Jul 22, 2021
Applicant: Advanced Semiconductor Engineering, Inc. (Kaohsiung)
Inventors: I-Jen CHEN (Kaohsiung), Guo-Cheng LIAO (Kaohsiung), Jyun-Chi JHAN (Kaohsiung), Hui-Chen HSU (Kaohsiung)
Application Number: 16/749,793